Nested macro recording does not work correctly

Originally reported by: **Chanchana Sornsoontorn (Bitbucket: [off99555](https://bitbucket.org/off99555), GitHub: [off99555](https://github.com/off99555))**

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Try `qaihelloq` to record macro `a` that just insert hello.
Then try `qb@a@aq` to try to insert hello 2 times.

And try to run `@b` you will notice that it repeats things too many time.
The problem is that, it just does not append `@a` to the `b` macro. But it also append the content inside macro `a` too!

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- Bitbucket: https://bitbucket.org/lyro/evil/issue/735

Reproduce the issue with the sequences `qaihelloq`, `qb@a@aq`, and `@b`, then trace the macro-recording and replay entry points. Done means macro `b` records the nested `@a` invocation rather than also copying macro `a`'s contents, so `@b` inserts “hello” twice.

Written by the indexing model from the issue text.